Various types of aircraft experience vibrations during operation. Such vibrations are particularly troublesome in rotary winged aircraft, such as helicopters, as vibrations transmitted by large rotors can contribute to fatigue and wear on equipment, materials, and occupants within the aircraft. Vibrations can damage the actual structure and components of the aircraft, as well as contents disposed within the aircraft. This increases costs associated with maintaining and providing rotary winged aircraft, such as costs associated with inspecting and replacing parts within the aircraft, which may become damaged during vibration.
Conventional methods of controlling vibration within an aircraft include using passive devices and/or systems, which are tuned relative to the operating frequency of the aircraft rotor. In addition to adding large amounts of weight to the aircraft, passive devices and/or systems are inefficient. More effective methods of controlling vibration within an aircraft include active devices and/or systems, which actively apply a control force to counteract forces imposed by aircraft vibration.
One problem associated with conventional active vibration control devices and/or systems, is that such systems fail to account for different vibration profiles occurring when an aircraft is at steady state versus in transient performance and/or at low and high forward air speeds. That is, currently available active vibration control devices and systems fail to account for changes to other aircraft information, such as forward air speed, rotor speed, altitude, etc., when generating control force commands, as those changes occur in real-time. Currently there is not an active vibration control device, system, or related method providing real-time modification of control parameters based upon real-time aircraft information.
Accordingly, there is a need for improved devices, systems, and methods for actively controlling aircraft vibration as the aircraft moves between transient and steady state conditions in real-time.